A well-known masonry building construction method uses dual walls consisting of a brick veneer or facade wall and a back-up wall that can be load bearing or constituted of various materials. The method is popular because it permits the use of a variety of aesthetically-pleasing outside wall materials, such as brick, concrete block, stone, terra cotta, or other similar materials. During construction, the facade wall and the back-up wall are mechanically or otherwise connected to ensure the structural integrity of both walls. Frequently, however, the exterior structural integrity and esthetics of such dual-wall systems degrade over time and lead to facade instability. A number of factors can cause or contribute to facade instability. For example, facade instability can occur because during construction the ties connecting the facade and back-up wall were omitted, were improperly placed, or were improperly installed. Facade instability can also occur because of excessive differential wall movement created by thermal movement, creep, moisture, and settlement. In addition, environmental factors can lead to corrosion of the tie elements used to connect the faced and back-up walls.
Remedial anchor wall systems are used to re-connect an existing facade wall to a back-up wall to thereby correct and overcome facade instability. One typical mechanical remedial wall anchor system consisting of a back-up anchor and a facade anchor attached to opposite ends of a central threaded bolt. The remedial system is used by first drilling a hole through the entire depth of the facade wall and through at least a portion of the depth of the back-up wall. The anchor system is then inserted into the hole with the back-up anchor placed in the back-up wall and the facade anchor placed in the facade wall. The two anchors are tightened or otherwise deployed to thereby re-connect the facade wall to the back-up wall. Finally, mortar can be applied to the facade wall to cover the hole containing the remedial anchor. A second type of remedial wall anchor system uses a tie-member embedded within and bonded to an adhesive-filled tubular wire screen to connect the tie-member to the facade and back-up walls.
Known remedial wall anchor systems, however, do not adequately correct facade instability in all types of dual wall structures. Some dual wall structures require reinforcing rods or wires embedded within the facade wall to increase the strength, ductility and stability of the facade wall. For example, building structures subject to seismic or wind loads frequently have a continuous reinforcing rod or wire embedded in the mortar of the facade wall. The rod or wire imparts additional stability and ductility to the dual-wall system and helps to counteract lateral stresses induced by in-plane and out-of-plane movement of the facade wall. The rod or wire is attached or otherwise connected to the wall anchors which tie the facade wall to the back-up wall. Known remedial wall anchor systems do not adequately correct facade instability in such building structures because the systems do not connect the reinforcing rods or wires to the anchor system. On the other hand, known wall anchor systems utilizing reinforcing rods or wires cannot be used to re-connect existing facade and back-up walls without removing and replacing large portions of the facade wall.
A need therefore exists for a remedial anchor wall system which connects the reinforcing rod or wire to a wall anchor system in an existing dual wall structure.